America marks the 22nd anniversary of the 9/11 terrorist attacks with solemn ceremonies and remembrance events held at various locations across the country. The nation honors the lives lost in New York's ground zero, the attack on the Pentagon, and the heroic actions of passengers in Shanksville, Pennsylvania. First responders, government officials, and family members of victims pay their respects and observe moments of silence at memorials and museums. American flags fly at half-staff, and wreaths are laid to remember the nearly 3,000 people who lost their lives in the deadliest terrorist attack on U.S. soil.